Let them eat cake or something

We have two truly outstanding science communicators in Australia. One is my colleague Robyn Williams. The other is Julian Cribb. Robyn is a broadcaster, the broadcaster really. Julian works for himself these days, rather than a paper, but he remains the doyen of science writers. He is clear, fluent and explains the otherwise inexplicable. His latest effort is as scary as something that rhymes with duck.

In a nutshell, the world is running out of food. One indicator is that our reserves of grains would not last two months. It's easy, in these days of no-wheat diets, to forget what that means. Grains are the great staple foods of the world - especially rice, maize and wheat. If we run out of grains, the planet goes to hell in a handbasket.

You may have noticed that filling your handbasket (alright, trolley) at the supermarket is costing more. Australia's drought has pushed up the prices of fruit, vegetables and meat. Lately, there's been increases in the cost of bread, flour, rice and the already exhorbitant breakfast cereals. That's because wheat, rice and barley have all become more expensive.

If you live in Australia, you're not going to starve. Food will get more expensive but not impossible to come by. Actually food really is going to get rather pricier. We've been living in an era of cheap food which has lasted for decades. (Though, as one of five children in a family growing up in the 70s, I remember when chicken was "too dear"). There are lots of reasons all this cheap food was possible, and this isn't the place to go through them all, but two are fundamental: land and water.

Much of the world's best arable land is now being paved over. Cities are built on it. And golf courses. (I am conflicted about golf courses - I find them beguilingly attractive but know that in most environments they are about the most wasteful use of land and resources). Even in Sydney, where I live, the arable land is vanishing because it's becoming too valuable to be farmed. That's one reason.

Another is that the world's topsoil, that magic, fertile layer 5-20 centimetres thick, is disappearing. Wind, farming practices and rain are taking it to the sea. And speaking of water, cheap food is predicated on cheap water. Mostly the water hasn't been so much cheap as ludicrously undervalued. This is gradually changing, and it may be that that supply and demand produce a tipping point where prices increase very rapidly indeed.

But if the end of cheap food in Australia is an inconvenience, or even another source of pressure on working families, that's as nothing to the impact we're already seeing in some parts of the world. There have been riots over food in the last couple of weeks - people have died.

Food and water security have been the great drivers of conflict throughout history. We have tended to focus on the who in these disputes - which people, which ethnic groups, which nations? But the why has usually been about resources - most of the time about food and water. Cribb points out that if people can't get food where they live, they move. The UNHCR currently helps almost 33 million people, who are either refugees or have been "internally displaced". That figure is likely to rise as global warming continues to impact on crop growth in Africa and Asia.

Julian Cribb is clear-eyed about what needs to happen - he suggests 12 changes that would make a difference. Among them, a massive investment in agricultural research; speeding up the transfer of new technologies to farmers the world over; the development of "green cities", which recycle their own water and waste and grow some of their own food.

The 2020 Summit is next weekend in Canberra. I do hope someone going will mention all this.